Throw an exception if a reservation is eaten by the GC. Better to die early with a known error than to desync later.

OpenRA.FileFormats/Primitives/DisposableAction.cs

@@ -14,22 +14,27 @@ namespace OpenRA
 {
 	public class DisposableAction : IDisposable
 	{
-		public DisposableAction(Action a) { this.a = a; }
+		public DisposableAction(Action onDispose, Action onFinalize)
+		{
+			this.onDispose = onDispose;
+			this.onFinalize = onFinalize;
+		}
 
-		Action a;
+		Action onDispose;
+		Action onFinalize;
 		bool disposed;
 
 		public void Dispose()
 		{
 			if (disposed) return;
 			disposed = true;
-			a();
+			onDispose();
 			GC.SuppressFinalize(this);
 		}
 
 		~DisposableAction()
 		{
-			Dispose();
+			onFinalize();
 		}
 	}
 }

OpenRA.Mods.RA/Reservable.cs

@@ -32,10 +32,10 @@ namespace OpenRA.Mods.RA
 		{
 			reservedFor = forActor;
 
-			return new DisposableAction(() =>
+			return new DisposableAction(() => { reservedFor = null; },
-				{
+										() => Game.RunAfterTick(() => 
-					reservedFor = null;
+			                        {throw new InvalidOperationException("Attempted to finalize an undisposed DisposableAction");})
-				});
+			);
 		}
 
 		public static bool IsReserved(Actor a)